Visual observation of a subject for changes in coloration indicative of a particular condition has often occurred. The subject may be a person or animal being observed to determine the presence or absence of a medical condition. The color characteristics or a single color characteristic of other test subjects such as biopsy specimens or excretions have diagnostic value.
An individual person's skin color is often assessed by her or his doctor. Hypertension, tuberculosis, sclerosis of the liver, to name just a few, are examples of ailments with symptomatic skin color changes among at least a sizeable population segment. Hair color evaluation and dental coloration evaluation are valuable. These may bear on the health of the individual, or on the health of the individual's hair and teeth, or these may permit accurate cosmetic activities, for example, to counteract graying or to accurately match new dental work to existing teeth.
Likewise, the condition of plants and agricultural products is visually inspected for color as an indication of condition. Contamination of soil is likewise apparent from visual inspection. Such visual inspections are subjective. Measuring by instrument the color characteristics that are key to the visual inspection has the benefit of objectivity and consistency.
In the past, hyperbilirubinemia in newborns has been detected by visually observing an individual for jaundice or by routinely taking and testing a blood sample. Upon detection, hyperbilirubinemia has been treated by phototherapy. During the course of phototherapy, blood samples have been taken and tested at regular intervals until it was determined that the level of serum bilirubin had decreased to an acceptable level.
In infants, there is little blood available for use in the blood testing for hyperbilirubinemia. So much blood is drawn that transfusions are often necessary to replace the drawn blood. The newborn is thereby exposed to all of the risks that transfusions bring. Blood sampling and transfusions are, of course, painful to the newborn, and as with any invasive procedure, both present medical risks, such as for example, risk of infection. There is a need, therefore, for a reliable, noninvasive technique for detecting and measuring a skin color affecting medical condition such as hyperbilirubinemia.
This is one example of a wider need for procedures and instruments to objectively and consistently determine a color characteristic or factor indicative of the condition of a test subject or indicative of a particular ailment or condition. The methods and apparatus of this invention can be employed where previously visual inspection, of which examples are given above, have been carried out at least in part on the basis of observable color characteristics.
This invention also relates to a method and apparatus for the categorizing of hair color and hair color treatment agents for their interrelationship, and more particularly to a process and instrument for measuring three color characteristics of hair color and categorizing it and determining the effect of a wide variety of hair coloring agents thereon.
Hair coloring agent choices are often made by a consumer based on relatively vague indications of the color to be expected as a result of the use of the agent on an individual person's hair. This approach does not take into consideration the color of the hair that is to be treated and how interaction of that particular individual's hair color with the coloring agent will affect the resultant color.
No reliable source of information has been available to a private consumer regarding what the actual color of her or his hair is and what hair coloring agent will provide the hair color alteration that consumer seeks.
Consequently it can be seen there exists a need for procedures and apparatus that will accurately characterize an individual's hair color to enable selection of appropriate coloring agents for a desired color result. Likewise there exists a need for a reliable process and instrumentation to permit the use of the accurate color characterization of an individual's hair color in the selection of hair coloring agents to effect hair color alterations of a type desired by the individual.